A New Zealand mayor who spent $4000 on a pair of camel shackles that he thought were once used to hold Maori prisoners during the 1800s has been lambasted for his mistake.

But Dunedin Mayor Dave Cull says he has 'no regrets' over the purchase despite new evidence showing they were used on camels, and not Maori warriors, the Otago Daily Times reported on Monday.

The council paid $3900 for the shackles in March for display at Toitu Otago Settlers Museum, in Dunedin, New Zealand.

Duped: Dunedin mayor Dave Cull paid almost $4,000 for leg cuffs he thought were used on Maori prisoners

But the museum's own investigation has found the seller's suggestion that the leg irons were found inside a cave near where Maori prisoners from Taranaki were forced to labour between 1869 and 1881 are just not credible.

Sean Brosnahan, one of the museum’s curators who carried out the research, said the cave never even housed Maori prisoners.

Instead, the shackles are believed to be of Middle Eastern origin from the early 20th century, and their size suggests they fit a camel or a Clydesdale-sized horse.

This has prompted the mayor to call on the seller - Dunedin man Steve McCormack - to 'examine his moral position' and consider refunding the purchase.

Misleading: The leg irons were reportedly found inside a cave near where Maori prisoners from Taranaki were forced to labour between 1869 and 1881, but the museum says this is not credible

That suggestion has earned the ire of the Taxpayers Union, an activist group, who have not held back in their criticism of the Dunedin mayor's spending decision.

'The mayor's shackles of stupidity provide the long-suffering Dunedin ratepayer with a smidgin of poetic irony, but that's little cause for celebration,' said its executive director Jordan Williams.

'Instead of begging a vendor to reimburse the money after the mayor's jumped the shark, it would be better if he simply stopped playing loose with ratepayers' money.'

Mr McCormack has rejected the idea of a refund and told the New Zealand Herald: 'If you go to auctions... it's a bit like going to the casino, I suppose, but at least you can come out of there with something.'

The shackles are believed to be of Middle Eastern origin from the early 20th century, and their size suggests they fit a camel (left) or a Clydesdale-sized horse. The shackles were found in a harbourside cave on Dunedin's Portobello Rd (right)

He also claimed he had never said they were definitely linked to Maori prisoners.

'I put them up for sale as a pair of leg irons. He [Mr Cull] stopped the auction - he took responsibility for it by doing that,' he said.

Between 1845 – 1872 there were land wars between the Maori population and the settlers on New Zealand's North Island.

In Dunedin, Maori prisoners of war were held in caves at the end of Portsmouth Drive at the beginning of the Otago Peninsula.

Near the caves today there is a memorial which was erected in memory of the Maori prisoners who died during their term of imprisonment.

The council paid $3900 for the shackles in March for display at Toitu Otago Settlers Museum, in Dunedin, New Zealand